1. Field of the Invention
Exemplary embodiments relate to a method and an apparatus for device-to-device (D2D) multicast communication in a cellular mobile communication system that may execute a D2D multicast or broadcast communication in a mobile communication system.
2. Description of the Related Art
Recently, a sharp increase in wireless data traffic deserving of being called a mobile big bang is taking place in a mobile communication system. One of the causes of increasing wireless traffic is a mobile social service that has a characteristic of an increasing amount of data exchanged between mobile terminals. To process a sharp increase in traffic of a mobile communication network, various off-loading methods have been studied to improve a wireless transmission rate, and in particular, a technology for direct communication between terminals based on mobile communication or a device-to-device (D2D) communication technology that increases a capacity of a radio resource and expands a coverage area of a cellular network through a direct communication between terminals is gaining attention these days.
A technology for direct communication between terminals based on fourth generation (4G) mobile communication such as long term evolution (LTE) has only recently been studied and discussed for standardization. A current technology enabling direct communication between mobile terminals may include, for example, wireless fidelity (WiFi) Direct or Bluetooth, and is based on a different frequency domain and technology from that of mobile communication.
A technology for direct communication between terminals based on mobile communication is similar to WiFi Direct or Bluetooth in terms of direct communication between mobile terminals, but there is a basic and significant difference in that a mobile terminal executes a direct communication between terminals using a frequency band used for communication with a base station. It is expected that this difference may lead to an increase in capacity and an expansion of a cell coverage of a mobile communication network and development of a differentiated application service. For example, when WiFi and Bluetooth functions are embedded together in a multimode in a mobile communication terminal like a majority of recent smart phones, a wireless function of mobile communication is generally always-on anywhere. This aims to reduce power of a multimode terminal and is a basic characteristic of mobile communication. Accordingly, it may be the most appropriate to use a wireless function of mobile communication in measuring proximity to search for a nearby terminal for direct communication between terminals.
As one of the technologies for direct communication between terminals based on mobile communication, reference may be made to Korean Patent Publication No. 10-2012-0100833, published on Sep. 12, 2012, titled “Method of executing direct communication between terminals and terminal for supporting the same”, in which a direct communication is executed between a first terminal and a second terminal using a common direct communication resources that is commonly allocated to all cells and has a fixed size and position.
However, as an international standardization organization has only recently started to discuss a technology for direct communication between terminals based on mobile communication, researches are being conducted over the world, but focus on a peer-to-peer direct communication technology between terminals still remaining at an initial level.
Accordingly, there is a demand for a method of providing a service via broadcast within a particular region to which it is expected to provide the service most effectively by applying a technology for direct communication between terminals in a mobile communication network, for example, regional advertising or regional broadcasting.